| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.lucene.analysis.miscellaneous; |
| |
| import org.apache.lucene.analysis.CharArraySet; |
| import org.apache.lucene.analysis.FilteringTokenFilter; |
| import org.apache.lucene.analysis.TokenStream; |
| import org.apache.lucene.analysis.tokenattributes.CharTermAttribute; |
| |
| /** |
| * A TokenFilter that only keeps tokens with text contained in the required words. This filter |
| * behaves like the inverse of StopFilter. |
| * |
| * @since solr 1.3 |
| */ |
| public final class KeepWordFilter extends FilteringTokenFilter { |
| private final CharArraySet words; |
| private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class); |
| |
| /** |
| * Create a new {@link KeepWordFilter}. |
| * |
| * <p><b>NOTE</b>: The words set passed to this constructor will be directly used by this filter |
| * and should not be modified. |
| * |
| * @param in the {@link TokenStream} to consume |
| * @param words the words to keep |
| */ |
| public KeepWordFilter(TokenStream in, CharArraySet words) { |
| super(in); |
| this.words = words; |
| } |
| |
| @Override |
| public boolean accept() { |
| return words.contains(termAtt.buffer(), 0, termAtt.length()); |
| } |
| } |